Cellular Respiration

Lies behind the left half of the sternum, opposite the 4th coastal cartilage.

Lies behind the left 1½ of the sternum, opposite the 3rd intercostal space (ICS).

Lies behind the right half of the sternum, opposite the 4th intercostal space (ICS).

Lies behind the medial end of the 3rd left coastal cartilage and adjoining part of the sternum.

Has 2 cusps (anterior and posterior), with the anterior cusp being larger. This valve intervenes between the A-V and aortic orifice.

Has 3 semilunar cusps (ant RT, post. wall LT and post).

Has 3 cusps (ant, septal and post).

Has 3 semilunar cusps, one posterior and two anterior (anterior and right).

Aortic stenosis in infants, children, and adolescents is often due to congenital aortic stenosis, subvalvular or supravalvular aortic stenosis.

Aortic stenosis in young to middle-aged adults can be caused by calcification/fibrosis of a bicuspid valve or rheumatic aortic disease.

In middle-aged to elderly individuals, aortic stenosis commonly results from calcification of a bicuspid valve or senile degenerative aortic stenosis.

Except in congenital forms, AS develops slowly. The LV becomes increasingly hypertrophied, potentially leading to inadequate coronary blood flow; outflow obstruction limits increases in cardiac output on exercise.

Symptoms: exertional dyspnea, angina, pulmonary edema, exertional syncope, and sudden death.

Signs: ejection systolic murmur, slow rising carotid pulse, reduced pulse pressure, LV hypertrophy, and signs of LV failure (crepitations, pulmonary edema).

Common investigations for AS include ECG, CXR, ECHO, and CATH.

Medical AS treatment is mainly for managing complications like heart failure or endocarditis. Primary is surgical.

Congenital: Bicuspid valve, or disproportionate cusps. Acquired: Rheumatic disease, infective endocarditis, trauma. Aortic dilatation: marfan syndrome, atheroma, syphilis, ankylosing.

Stroke output doubles/trebles. LV dilates & hypertrophies, leading to increased end-diastolic volume, diastolic filling pressure, and pulmonary issues.

Mild AR may be asymptomatic or involve palpitations; severe AR showcases heart failure or angina.

Signs: large volume or 'collapsing' pulse, bounding peripheral pulses, early diastolic murmur, systolic murmur of increased stroke volume, signs of heart failure.

Common tests include ECG, CXR, MRI/CT scan, ECHO, and CATH.

Treat asymptomatic patients with chronic severe AR and dilated, but normal, LV systolic function medically; consider surgery in some cases; acute AR treated surgically.

Valve replacement can be mechanical or bioprosthetic.

A mechanical valve has better durability and requires lifelong warfarin.

A bioprosthetic/tissue valve doesn't need lifelong warfarin but has less durability.

Mitral stenosis results from long-term damage to the mitral valve and its supporting structures, often from rheumatic heart disease.

Normal mitral valve orifice cross-sectional area is 4-6 cm². Significant MS starts < 2cm² and gets critical < 1cm²; causes pulmonary vasoconstriction and hypertension.

Progressive Dyspnea (70%): LA dilation & pulmonary congestion; Increased pressures lead to left atrial enlargement and fibrillation; right HF and hemoptysis may show.

Common signs are AF, loud first heart sound, opening snap, mid-diastolic murmur, pulm capillary raise, pul HTN.

Tests: ECG for LA hypertrophy, CXR for mitral stenosis and pulmonary hypertension, ECHO for valve area

Medical management requires yearly follow ups. Use diuretics for CHF, RX for Tachyarrhythmias, and fibrillation/flutter circuits.

Includes symptomatic mitral stenosis, mitral valve less than 1 cm², mitral valvotomy. Commissurotomy consists incision of fused mitral valve.

Mitral valve replacement with mechanical valve or bioprosthesis.

Chordae are rupture due to acute myocardial, Perforation of the mitral valve leaflet, acute failure of a prosthetic valve.

Mitral valve prolapse and rheumatic heart disease, Coronary artery disease, prosthetic valve cause the mitral Regurgitation

Distensibility of the LA and LV are increased over time, dilatation of the left atrium, and left ventricle dilatates, stroke volume increasing.

In acute, there is acute pulm edema and reduced CO. Exertional dyspnea, pulmonary increase, CO diminished, Sx of right sided HF for

Tests

ECG can look for LAH and LVH while CXR focuses and Pulm Edema. ECHO searches Regurgitation detects on Doppler

Any patient that is compromising is evaluated and given Afterload reducing agents. Antibiotics for preventative measure.

Acute MR when congested leads to surgery, endocarditis, patient are symptomatic, and there is systemic Emboli.

Annulus are reduced when there is leaflet. Split and shortened to a point, while muscles split to adjust.